Organic thin film transistors (OTFTs) (that is, thin film transistors having an organic semiconductor) are gaining attention as a technology that enables a variety of applications centered around low-cost electronics. It is believed that organic semiconductors can be synthesized to incorporate the necessary electronic properties for a wide variety of devices. These devices can also be constructed to allow low-cost, reel-to-reel processing that is not currently possible for crystalline silicon microelectronics.
One area of concern, however, in organic electronic devices is the quality of the interface formed between the organic semiconductor and the gate dielectric. Efforts to control the semiconductor/dielectric interface such as, for example, interposing a polymeric layer between the organic semiconductor and the gate dielectric (see, for example, U.S. Pat. No. 6,617,609 (Kelley et al.) and U.S. patent application Ser. No. 03/0102471 (Kelley et al.)) have led to improvements in device properties.
Typically, these polymeric interface layers are solution deposited, for example, by spin-coating or similar techniques. In many instances, however, the other layers of the OTFT (for example, the gate electrode, the gate dielectric, the organic semiconductor, and the source electrode and drain electrode) are vapor deposited. Therefore, in order to solution deposit a polymeric interface layer on an otherwise vapor deposited transistor, a partially complete transistor must be removed from the vacuum chamber between vapor deposition of the gate dielectric and the organic semiconductor, and then returned to the chamber.